Articles requiring a degree of elasticity have been formed by combining elastic materials with inelastic, or less elastic, materials through various lamination processes. Often, such composite laminate articles will be stretchable because of the presence of the elastic material and the particular manner in which the elastic and inelastic materials have been bonded together during the laminating process.
Typically, such stretchable laminates are formed by joining the inelastic material to the elastic material while the elastic material or sheet is in a stretched condition. After such joining of the materials, the laminated article is then allowed to relax, which results in the inelastic component gathering in the spaces between bonding sites on the elastic sheet. The resulting laminate article is then stretchable to the extent that the inelastic material gathered between the bond locations allows the elastic material to elongate. Examples of these types of composite laminate articles and materials are set forth in U.S. Pat. Nos. 4,720,415 and 5,385,775, each of which is incorporated herein by reference thereto.
In some stretchable laminate articles, elastic strands of continuous filaments are bonded to relatively inelastic sheet materials while the elastic strands are in a stretched condition. Such elastic continuous filaments may, in certain articles, be sandwiched between two or more relatively inelastic sheets. The relatively inelastic sheets may include nonwoven webs formed by meltblowing or spunbonding various polymers. Examples of such laminates are shown in U.S. Pat. No. 5,385,775; in U.S. Pat. No. 6,057,024; and in U.S. Published Patent Application No. U.S. 2002/0104608, which are all incorporated herein by reference.
In the past, an adhesive was used in order to adhere the elastic strands of continuous filaments to the sheet materials. In one embodiment, for instance, the adhesive was sprayed on the sheet material prior to contacting the filaments forming an adhesive layer in between the sheet material and the filaments. Spraying the adhesive material onto the sheet materials, however, may have some drawbacks in various applications. For instance, spray devices may be difficult to control leading to over-application of the adhesive or leading to a non-uniform coverage of the adhesive on the sheet material, especially at high machine speeds and at low application rates. In fact, over-application of a hot adhesive during a spray process may cause filament breakage and machine downtime. Further, since the adhesive has to travel a distance prior to contacting the sheet material, the adhesives may experience a loss in tack prior to contacting the sheet material.
In view of the above, a need currently exists for an improved method for bonding an elastic member to a facing material. A need also exists for an elastic composite laminate that has improved properties and/or characteristics due to the manner in which the layers are combined together.